Q: What would make my camshaft positioning sensor keep messing up on my 2007 Ford F-150 fx4 with a 5.4 liter. I replaced it twice

The sensor itself can and should be tested prior to condemning it. In addition to a functioning sensor, the circuit back to the PCM must be intact and not have any loose connections, corrosion or high resistances. It is not likely that the sensor would fail multiple times and indeed the first sensor might have been perfectly good (unless it was tested directly; a code "implicating" the sensor or sensor circuit can never be the sole basis to replace the sensor; instead, sensor output must be viewed directly on a scope to diagnose the sensor/circuit) and the problem is simply in the circuit wiring/connections. To get this resolved, the recommended service to request is a check engine light diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.